Erosible nozzle for roller bit



Aug-1s; 1959 E. A. MILLER ETAL 2,900,171 EROSIBLE NO'ZZLE- FOR ROLLERBIT 2 Sheets-Sheet 1 Filed May 19, 1952- fluke A. dob/7600 5/1/00 A.M///er INVENTORJ y. WM 244m 2' Aug-1s, 1959 I E. A. MILL R EI'AL2,900,171

'EROSIBLE NOZZLE FOR ROLLER BIT Filed May 19. 195 2 v 2 Sheets-Sheet 2Duke 4/0/7/760/7 5/1 06 /4.-M///er INVENTORJ QWM 77710-21, BY 0 2,5. MEKM ATTORNEY) EROSIBLE NOZZLE non ROLLER BIT Elvas A. Miller and Duke A.Johnson, Oklahoma City,

Okla., assignors to Reed Roller Bit Company, Houston, Tex., acorporation of Texas This invention relates generally to drill bits andmore particularly to the means in roller drill bits for directingdrilling fluid pumped therethrough.

In the drilling of deep wells, a drill bit is attached to the end of adrill stem and lowered to the bottom of the hole. The drill stem is thenrotated causing the drill bit to penetrate the formation, and drillingfluid is pumped downwardly through the drill stem and drill bit toremove the cuttings dislodged by the drilling operation and carry themupwardly, in the space between the drill stem and the wall of the hole,to the surface of the earth. Drill bits in common use may be providedwith rollers to cut or crush the formation, and may be provided withnozzles to discharge drilling fluid toward the bottom of the hole, sothat cuttings or particles of formation dislodged by the bit during thedrilling operation may be removed from the bottom of the hole. However,in certain instances, the drill bit may become packed or balled up whenlowered by the drill stem to the bottom of the hole; that is, thecuttings dislodged by previous drilling operations, and other materialor detritus already in the hole, may accumulate about the rollers andpack the drill bit, as the drill bit.is being lowered into the hole.Balling up of the drill bit may occur particularly in those roller bitsin which the drilling fluid is discharged from the bit head toward thebottom of the hole. Accordingly, the nozzles serving to discharge thedrilling fluid toward the bottom of the hole may not serve to clean therollers and adjacent parts properly. As a result of this, the rollersmay not freely rotate when the drill stem is rotated and the bittherefore does not efficiently drill the formation.

A general object of this invention is to provide a drill bit having newand improved nozzles which will serve not only to discharge fluiddirectly toward the bottom of the hole but also to clean the bit ofaccumulated cuttings and detritus.

A specific object is to provide a new and improved bit in which thedrilling fluid pumped through the drill stem will be initially utilizedto clean the drill bit and, after the bit has been cleaned, the drillingfluid will be discharged directly toward the bottom of the hole toremove the cuttings dislodged by the bit during the drilling of thewell.

Another specific object is to provide a nozzle having a diverter whichwill cause drilling fluid pumped through said nozzle initially to cleanthe drill bit; said diverter being adapted to be rendered ineffectivethereafter by the action of the drilling fluid, whereupon said nozzlewill gislcharge the drilling fluid toward the bottom of the Otherobjects will hereinafter appear from the following description and theaccompanying drawings wherein, by way of example, one embodiment of thisinvention is set forth.

In the drawings:

Fig. 1 is a section taken on line 1-1 of Fig. 2.

United States Patent Patented Aug. 18, 1959 ice Fig. 2 is a bottom planview of a drill bit showing the positions of the drilling fluid nozzlesin the bit.

Fig. 3 is a fragmentary sectional view showing thedrilling fluiddiverter.

Fig. 4 is a fragmentary sectional view showing the drilling fluiddiverter after it has been rendered inefiective by the action of thesaid fluid.

Fig. 5 is an isometric view showing in detail the drilling fluiddiverter attached to the lower end of the fluid nozzle.

Referring to Figs. 1 and 2, the drill bit is indicated generally by thecharacter A and the bit head is indicated at 1. The bit head 1 may haveoppositely disposed side roller bearing extensions 2 and oppositelydisposed cross roller bearing extensions 3. Side rollers 4 may berotatably mounted in the usual manner on said side roller bearingextensions 2 and cross rollers 5 and 6 may be rotatably mounted in theusual manner on cross roller bearing extensions 3. The inner ends of thebearing extensions 2 and 3 may be secured to a bridge 15. The bit has athreaded shank 7 which is adapted to be connected to a drill stem (notshown). As can be seen in Fig. 1, a drilling fluid nozzle 8 is disposedwithin the bore 9 of the shank 7. The nozzle 8 has downwardly andoutwardly diverging fluid passageways It). The low er ends 11 of thenozzle 8 may be directed to discharge drilling fluid toward the bottomof the hole. A wear resisting insert 16 may be provided in the lower end11 of the nozzle 8. A drilling fluid diverter 12 is attached to the end11 by means of brazing or other suitable means. The diverter 12 isadapted to divert initially drilling fluid, being discharged from theends 11 of the fluid nozzle 8, toward the rollers 4, 5 and 6 and towardthe recess 13 immediately above the said rollers. The recess 13 abovethe said rollers is formed by the lower portion of the bit head 1, theside roller bearing extensions 2 and the cross roller bearing extensions3.

As shown in Fig. 5, the diverter 12 may be in the form of a hollowspherical wedge, a quarter of a spherical shell or any other suitableshape. The diverter 12 may have a saw-cut 14 or other separation or maybe 1 scored for the purpose of accelerating the erosion thereof causedby the'action of the drilling fluid impinging thereon. The diverter 12may be made of sheet metal or other suitable material. Thus it can beseen that the diverter 12 will initially act to divert the drillingfluid being pumped through the drill stem and through the drilling fluidnozzle substantially inwardly towards the drill bit to remove detritusand cuttings which may have accumulated about said cutters and in therecess 13, as the drill bit was beiig lowered into the hole. Continuedimpingement of the drilling fluid upon the diverter 12 will cause it tobecome inoperative and it may become eroded away by the action of thedrilling fluid impinging on the said diverter.

Fig. 3 shows schematically how the diverter 12 may act to direct thedrilling fluid to clean the drill bit rollers and adjacent parts, and inFig. 4, the diverter 12 is shown after having been rendered inoperativeby the action of the drilling fluid impinging thereon, whereupon thedrilling fluid now is directed toward the bottom of the hole and is nolonger being diverted towards the drill bit rollers by the diverter 12.

In operation, the drill bit A is secured by means of a threaded shank 7to the end of a drill stem (not shown) which is then lowered to thebottom of the bore hole and rotated to cause the drill bit-to penetratethe formation. During the lowering thereof, the drill bit may havebecome ,balled up or packed with cuttings standing in the hole, whichhave been dislodged during previous drilling operations. The cuttingsmay accumulate about the side rollers 4 and cross rollers 5 and 6 and 3especially in the recess 13 above said rollers. The drill bit may thusbecome bailed up before it is rotated on the bottom of the hole. Thisballing up or packing of the drill bit maybe so severe that the rollersmay not turn properly, upon rotation of the drill stem, and thus mayskid and be worn flat, materially reducing the useful life of the drillbit. In order to alleviate this condition, -we have provided thedrilling fluid diverter 12 which will act initially to divert drillingfluid being pumped through the drill stem to clean the drill bit of thecuttings and detritus packed therein, as above described. Continuedimpingement of the drilling fiuid on the said drilling fluid diverter 12will cause it to become inoperative to divert said fluid; whereupon, thefluid will then be directed toward the bottom of the hole to removetherefrom the cuttings dislodged during the drilling operation.

Our invention is not limited to the embodiment shown. Various changes,within the scope of the following claims, will be apparent to thosefamiliar with the art.

We claim:

1. A cross roller bit having a head, cross rollers and side cuttersmounted in the lower portion of said head with a recess formedthereabove, said head having a drilling fluid discharge passagewayprovided with a nozzle at its discharge end for directing the drillingfluid in a straight line course, means for diverting the drilling fluidfrom said straight line course and turning it inwardly towards saidcutters consisting of a hollow substantially spherical thin-walled metalmember having a portion thereof open and inwardly directed towards saidcutters and mounted on the lower end of said passageway whereby saiddrilling fluid is initially turned toward the central portion of the bitso as to be directed onto said rollers and cutters and into said recessto clean the bit, said diverting means having a portion of its wallwhere the straight line directed drilling fluid impinges thereagainstpreliminarily weakened so that the drilling fluid will by eroding actionultimately destroy substantially all of said diverting means whereby theformerly inwardly turned drilling fluid is again returned to itsstraight line course and directed toward the bottom of the hole beingdrilled by said bit.

2. A cross roller bit having a head, cross rollers and side cuttersmounted in the lower portion of said head with a recess formedthereabove, said head having a drilling fluid discharge passagewayprovided with a nozzle at its discharge end for directing the drillingfluid in a straight line course, means for diverting the drilling fluidfrom said straight line course and turning it inwardly toward saidcutters consisting of a substantially spherical thin-walled metal memberhaving an outer wall portion, a weakened bottom wall portion and aninwardly directed open wall portion directed towards said cutters andmounted on the lower end of said passageway whereby said drilling fluidis initially turned toward the central portion of the bit so as to bedirected onto said rollers and cutters and into said recess to clean thebit, said weakened bottom wall portion serving to form a surface againstwhich the straightline directed drilling fluid may impinge and byeroding action ultimately destroy substantially all of said divertingmeans whereby the formerly inwardly turned drilling fluid is againreturned to its straight line course and directed toward the bottom ofthe hole being drilled by said bit.

3. A cross roller bit having a head, cross rollers and side cuttersmounted in the lower portio of said'head with a recess formedthereabove, said head having a drilling fluid discharge passagewayprovided with a nozzle at its discharge end for directing the drillingfluid in a straight line course, means for diverting the drilling fluidfrom said straight line course and turning it laterally inwardly 'withrespect to the sides of said bit head and towards said cuttersconsisting of a hollow substantially spherical thin-walled metal memberhaving a portion thereof open and inwardly directed towards said cuttersand mounted on the lower end of said passageway whereby said drillingfluid is initially turned toward the central portion of the bit so as tobe directed onto said rollers and cutters and into said recess to cleathe bit, said diverting means having a portion of its wall where thestraight line directed drilling fluid impinges thereagainstpreliminarily weakened so that the drilling fluid will by eroding actionultimately destroy substantially all of said diverting means whereby theformerly inwardly turned drilling fluid is again returned to itsstraight line course and directed toward the bottom of the hole beingdrilled by said bit.

References Cited in the file of this patent UNITED STATES PATENTS GageApr. 22, 1941

